Support recursive project dependencies

1 files changed, 24 insertions, 6 deletions

diff --git a/src/main/java/org/shedlang/compiler/ShedCompiler.java b/src/main/java/org/shedlang/compiler/ShedCompiler.java
index af47ff5c..34cdad23 100644
--- a/src/main/java/org/shedlang/compiler/ShedCompiler.java
+++ b/src/main/java/org/shedlang/compiler/ShedCompiler.java
@@ -36,12 +36,7 @@ public class ShedCompiler {
     ) throws IOException, InterruptedException {
         var config = ProjectConfig.read(projectRoot);
 
-        // TODO: recursive dependencies
-        var projectRoots = new ArrayList<Path>();
-        projectRoots.add(projectRoot);
-        for (var dependency : config.dependencies()) {
-            projectRoots.add(dependency.path());
-        }
+        var projectRoots = findProjectRoots(config);
 
         var untypedNamespaceNodes = projectRoots.stream()
             .flatMap(root -> {
@@ -102,6 +97,29 @@ public class ShedCompiler {
         );
     }
 
+    /**
+     * Find the roots of any projects that require compilation, including
+     * transitive dependencies.
+     */
+    private LinkedHashSet<Path> findProjectRoots(ProjectConfig config) throws IOException {
+        var projectRoots = new LinkedHashSet<Path>();
+        var pendingProjects = new ArrayDeque<Path>();
+        pendingProjects.add(config.root());
+        // TODO: detect cycles
+
+        while (!pendingProjects.isEmpty()) {
+            var projectRoot = pendingProjects.removeFirst();
+            if (projectRoots.add(projectRoot)) {
+                var projectConfig = ProjectConfig.read(projectRoot);
+                for (var dependency : projectConfig.dependencies()) {
+                    pendingProjects.add(dependency.path());
+                }
+            }
+        }
+
+        return projectRoots;
+    }
+
     private List<Path> collectSourceFilePaths(Path sourceRoot) throws IOException {
         var paths = new ArrayList<Path>();
         Files.walkFileTree(sourceRoot, new SimpleFileVisitor<Path>() {